Acromegaly is a condition caused by excess secretion of growth hormone (GH). In almost all cases the excess GH is produced by a tumor of the anterior pituitary gland. Acromegaly is diagnosed by recognition of classic physical changes such as enlargement of the hands or feet, prominence of the jaw or brow, symptoms such as excess sweating or the development of hypertension or diabetes mellitus. The disease is confirmed by elevated GH levels, failure of GH to suppress after an oral glucose load and an elevated insulin like growth factor 1(IgF1) level. Standard initial treatment for acromegaly is surgical removal of the tumor. Recently, some studies have found that surgery for acromegaly is needed to better define the role of surgery in treatment of this disease. The purpose of this study is to establish the long term cure rate of pituitary surgery for acromegaly at this institution from 1980 to 1991. The study will consist of a retrospective chart review of 120 patients operated on during this period by one pituitary neurosurgeon and an assessment of these patients' current status by measurement of endocrine hormones.